UNIVERSAL M-25XP SHUTS DOWN
- Thread starter Debevoise
- Start date
Yes, on my M35B, to save the engine if engine oil flow is low or oil pressure is low, the oil pressure switch will cut the power to the fuel pump and stop the engine.
Joe, thanks for the reply. That seems like a good feature to have but it wasn't available on the M-25XP.
I recently changed the filters, and cleaned the one in the lift pump. My working theory is fuel starvation, so there are two issues I believe need to address: the possibility of crud in the tank blocking the pickup, or bad hoses that allow just enough fuel to get the engine started and not enough to motor anywhere.
I recently changed the filters, and cleaned the one in the lift pump. My working theory is fuel starvation, so there are two issues I believe need to address: the possibility of crud in the tank blocking the pickup, or bad hoses that allow just enough fuel to get the engine started and not enough to motor anywhere.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 23,546
The description of the engine shutting down in the original post sounds like fuel starvation is the cause.
If you have the same symptoms, my first action would be to ensure I have a clean fuel flow system from the tank to the injectors.
As @Stu Jackson has posted, depending on the type of fuel filters you are using, there may be a check valve in the fuel filter intake. That valve caused problems for Stu. You can find the issue/solution described here on the SBO forum. Search for "Fuel Check Valve" and Stu's name in the member block.
Other than that sneaky issue, the rest is straightforward. Open and clean all hoses and connections. Install clean new filters. Treat your tank to a cleaning, polish your fuel, or try to treat the tank with additives that will kill any diesel bugs, then flush them through your filters and replace them.
If you have the same symptoms, my first action would be to ensure I have a clean fuel flow system from the tank to the injectors.
As @Stu Jackson has posted, depending on the type of fuel filters you are using, there may be a check valve in the fuel filter intake. That valve caused problems for Stu. You can find the issue/solution described here on the SBO forum. Search for "Fuel Check Valve" and Stu's name in the member block.
Other than that sneaky issue, the rest is straightforward. Open and clean all hoses and connections. Install clean new filters. Treat your tank to a cleaning, polish your fuel, or try to treat the tank with additives that will kill any diesel bugs, then flush them through your filters and replace them.
I also just spoke with a local diesel mechanic experienced with Universal engines. He mentioned the fuel pickup hose and the possibility of a clogged filter in the tank. I'm going to try to pull it and inspect it today/tomorrow. It really is the final part of the system and I haven't inspected it yet.
Well, I took the fittings off of the top of the tank and found the riser was a welded aluminum tube and not the earlier plastic. This is an improvement but it means I couldn't easily check if there was a screen on the end. After carefully bleeding the system at several points, and checking if the glow plugs were getting 12v. the engine started. The issue was fuel flow, probably caused by incomplete bleeding. I'm still concerned by the fact that the tank has probably never been cleaned since it was installed in 1988, and there is likely crud at the bottom and possibly algae.
I found that there is a mechanic that will polish the fuel and clean the tank after I'm out for the season. Because there is no inspection port I believe this will be done through the fuel filler opening. It will be a good excuse to remove and replace the filler and vent hoses.
Once that is done I will be re-arranging the fuel delivery system to add an initial filer prior to the lift pump.
Current setup: Tank (with or without a screen on the feed tube) --> lift pump (Facet w/screen inside) --> Racor R12S 2 micron filter w/ removable plastic bowl --> Donaldson P550127 17 micron filter on engine. I don't know why the 2 micron is in front of a 17 micron filter, that makes no sense.
Future setup: Tank (cleaned) --> Racor 200 series, 30 micron --> Lift pump --> Racor 100 series, 10 micron --> 2 micron filter on engine.
I like the R500 series, but I don't think that level of fuel flow is essential. Maybe if I can find a used R500 housing, and some room to mount it, I'll consider using that as the initial filter and incorporate a polishing system.
I found that there is a mechanic that will polish the fuel and clean the tank after I'm out for the season. Because there is no inspection port I believe this will be done through the fuel filler opening. It will be a good excuse to remove and replace the filler and vent hoses.
Once that is done I will be re-arranging the fuel delivery system to add an initial filer prior to the lift pump.
Current setup: Tank (with or without a screen on the feed tube) --> lift pump (Facet w/screen inside) --> Racor R12S 2 micron filter w/ removable plastic bowl --> Donaldson P550127 17 micron filter on engine. I don't know why the 2 micron is in front of a 17 micron filter, that makes no sense.
Future setup: Tank (cleaned) --> Racor 200 series, 30 micron --> Lift pump --> Racor 100 series, 10 micron --> 2 micron filter on engine.
I like the R500 series, but I don't think that level of fuel flow is essential. Maybe if I can find a used R500 housing, and some room to mount it, I'll consider using that as the initial filter and incorporate a polishing system.
